Pulmonary Stenosis

Heart With Pulmonary Stenosis

Pulmonary stenosis refers to a narrowing of the pulmonary valve. Normally, deoxygenated blood flows from the right ventricle through the pulmonary valve to the lungs to be oxygenated. In the event of pulmonary stenosis, the right ventricle must work harder to pump all of the blood through the stenotic valve. This may result in a thickening of the right ventricular wall (hypertrophy).

Standard treatment is a balloon valvuloplasty. This procedure involves the insertion of a heart catheter through a vein in the leg leading to the heart. A balloon at the tip of the catheter is positioned over the stenotic valve and inflated to stretch open the valve. In rare cases the child may require surgical repair.

What Is Normal Cardiac Anatomy?

When your child has a congenital heart defect, there's usually something wrong with the structure of his or her heart's structure.

Heart With Normal Cardiac Anatomy

When your child has a congenital heart defect, there's usually something wrong with the structure of his or her heart's structure.

The heart is composed of four chambers. The two upper chambers, known as atria, collect blood as it flows back to the heart. The two lower chambers, known as ventricles, pump blood with each heartbeat to the two main arteries (the pulmonary artery and the aorta). The septum is the wall that divides the heart into right and left sides. The atrial septum separates the right and left atria; likewise, the ventricular septum separates the two ventricles.

There are four valves that control the flow of blood through the heart. These flap-like structures allow blood to flow in only one direction. The tricuspid and mitral valves, also known as the atrioventricular valves, separate the upper and lower chambers of the heart. The aortic and pulmonary valves, also known as the arterial valves, separate the ventricles from the main arteries. Oxygen-depleted blood returns from the body and drains into the right atrium via the superior and inferior vena cavas. The blood in the right atrium then passes through the tricuspid valve and enters the right ventricle.

Next, the blood passes through the pulmonary valve, enters the pulmonary artery, and travels to the lungs where it is replenished with oxygen. The oxygen-rich blood returns to the heart via the pulmonary veins, draining into the left atrium. The blood in the left atrium passes through the bicuspid, or mitral, valve and enters the left ventricle.

Finally, the oxygen-rich blood flows through the aortic valve into the aorta and out to the rest of the body.

More to Know

Babies with tetralogy of Fallot can have cyanosis, which is a bluish-purple color to their skin, lips, and fingernails. This happens when not enough blood reaches the lungs to get oxygen. They may also fail to gain weight, have difficulty feeding or breathing, and have enlarged skin or bones around the fingernails (known as clubbing).

Tetralogy of Fallot develops in utero while the heart is forming. A specific cause hasn't been determined, but babies with certain genetic disorders are at higher risk for developing it. Other risk factors include advanced maternal age and, during pregnancy, poor nutrition, diabetes, or certain viral illnesses.

Keep in Mind

Tetralogy of Fallot is a serious condition that requires young infants to have heart surgery to repair the defect. The good news is that most babies recover fully and thrive into adulthood. They will, however, need to be monitored closely by a heart specialist for the rest of their lives.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.